Potential benefits of antihypertensive therapy in NAFLD: results from an experimental model

Abstract Background and introduction Non-alcoholic fatty liver disease (NAFLD) is considered as the most frequent cause of chronic hepatic disease in adults. It is strictly correlated with insulin resistance. The renin-angiotensin system (RAS) has been correlated to the whole basic physiopathogenic mechanism of NAFLD in experimental models. Systemic arterial hypertension has been suggested to be associated with NAFLD in approximately 40% of the cases, and NAFLD has been independently associated with an increased risk of arterial hypertension in observational studies. Therefore, we can infer that treating arterial hypertension in NAFLD carriers will often be necessary and that the potential beneficial effects of the antihypertensive might, in this context, influence the choice of the respective drug. Purpose We aimed to evaluate the effects of the renin-angiotensin system blockade with angiotensin-converting enzyme inhibitor ramipril and angiotensin 2 type 1 receptor antagonist olmesartan, both used preventively, in NAFLD induced in rabbits fed a hypercholesterolemic diet and compared the results between the groups. Methods Forty-one rabbits were divided into four groups (normal, control, olmesartan and ramipril). The control, olmesartan and ramipril group were fed a hypercholesterolemic diet. Animals from olmesartan group were treated with olmesartan 1mg/kg/day and animals from ramipril group with ramipril 0.35 mg/kg/day. At the end of the 8th week, all rabbits underwent segmental hepatic resection and were euthanised. Blood samples were collected to determine glucose, creatinine, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and aminotransferase levels at baseline and euthanasia. Haematoxylin and eosin and Gomori trichrome stained slides were analysed based on the histological scoring system for NAFLD. Results The comparison between two groups (olmesartan with placebo and ramipril with placebo) showed that olmesartan and ramipril significantly diminished the development of steatosis (p=0.015, p=0.032), lobular inflammation (p<0.001, p=0.006), hepatocellular ballooning (p<0.001, p=0.023) and fibrosis (p=0.001, p=0.02). Based on NAFLD activity score, olmesartan and ramipril significantly reduced the development of nonalcoholic steatohepatitis (p<0.001, p=0.003). The comparison between olmesartan and ramipril showed that results were similar in all histological parameters evaluated (p=1, p=0.454, p=0.454, p=0.195, p=0.078). Conclusion(s) The preventive use of olmesartan and ramipril attenuates similarly, the development of hepatic steatosis, lobular inflammation, hepatocellular ballooning and fibrosis in hypercholesterolemic rabbits and based on NAFLD activity score both significantly reduced the development of nonalcoholic steatohepatitis. Funding Acknowledgement Type of funding source: None